Yet more evidence that commercial brewers do not mash at 5.2 to 5.6 pH ...

[day_trippr]

Minor nit: I'd be surprised if there are any ATC implementations that actually cover "any given temperature", and suspect 154°F would be well over the typical effective range.
For a couple of examples, both my Apera pH60 and Hach Pocket Pro Plus meters claim ATC effectivity is limited to the range of 0 – 50˚C (32 – 122˚F), and my retired Hanna 98128 says -5 to 50°C (23 to 122°F)...

Cheers!

 

[ep_brew]

The Extech PH100 / PH110 manual says: Temp. Compensation Automatic from 32 to 194F (0 to 90C)
Just putting that out there, I don't own one.

 

[day_trippr]

Well then...as the sensors and guts of many meters are clearly shared between mfgrs there could be others with that same upper spec out there.
Perhaps I just managed to miss them all with my purchases over the years

Cheers!

 

[Qhrumphf]

The benchtop meter i use at work can do ATC up to 100C. Its probe however is only rated for 50C.

 

[ScrewyBrewer]

Last year Red Tank Brewing in New Jersey brewed a 10 barrel batch of my TIPA recipe using my pH calculations. The brewery's expensive pH meter was used to sample the wort at mash temperature it measured 5.0 pH. After cooling the sample down to room temperature using my personal pH meter the sample measured 5.19 pH.

 

[Silver_Is_Money]

I was looking into the new Viking zero-Lox Pilsner malt online a bit today and came across Vikings recommendations for mash and boil pH. The attached shows the ideal mash pH is recommended as 5.6, and the ideal boil pH is recommended at 5.0. Just another piece for the mashing is not optimally done at a room temperature 5.4 puzzle. Here is the document from Viking Malts:

https://www.vikingmalt.com/wp-content/uploads/2017/10/No-Lox-Lager.pdf

 

[doug293cz]

I was looking into the new Viking zero-Lox Pilsner malt online a bit today and came across Vikings recommendations for mash and boil pH. The attached shows the ideal mash pH is recommended as 5.6, and the ideal boil pH is recommended at 5.0. Just another piece for the mashing is not optimally done at a room temperature 5.4 puzzle. Here is the document from Viking Malts:

https://www.vikingmalt.com/wp-content/uploads/2017/10/No-Lox-Lager.pdf

I don't see anything in that pdf about pH measurement temp.

Brew on

 

[dmtaylor]

I was looking into the new Viking zero-Lox Pilsner malt online a bit today and came across Vikings recommendations for mash and boil pH. The attached shows the ideal mash pH is recommended as 5.6, and the ideal boil pH is recommended at 5.0. Just another piece for the mashing is not optimally done at a room temperature 5.4 puzzle. Here is the document from Viking Malts:

https://www.vikingmalt.com/wp-content/uploads/2017/10/No-Lox-Lager.pdf

Blasphemy! Say it ain't so!

I don't see anything in that pdf about pH measurement temp.

Brew on

Well, true, they kind of don't...

 

[cire]

pH measurements are taken at standard temperature unless otherwise quoted.

 

[dmtaylor]

pH measurements are taken at standard temperature unless otherwise quoted.

That would be true, for scientists... except for the fact that many (most?) brewers are not scientists.

 

[ScrewyBrewer]

Sampling wort pH consistently, at room temperature, eliminates any variance in pH due to temperature. Which is a good thing.

 

[Silver_Is_Money]

I don't see anything in that pdf about pH measurement temp.

Brew on

If it's 5.6 at mash temperature, that would mean 5.8 to 5.85 at room temperature. So it's most likely intended to be room temperature.

 

[Brewbuzzard]

Ok, I have a question. If you have a pH reading at a standard mash temperature isn't that the actual pH that is affecting the mash efficiency and not what it would be at room temperature. We don't mash at room temperature.

 

[doug293cz]

Ok, I have a question. If you have a pH reading at a standard mash temperature isn't that the actual pH that is affecting the mash efficiency and not what it would be at room temperature. We don't mash at room temperature.

If you measure at mash temp, with a pH meter that is calibrated correctly, then yes, that is the mash temp pH. The problem with a lot of literature is that the authors don't specify the temp at which they took their measurements. That's pretty much the whole reason for this thread.

Brew on

 

[Silver_Is_Money]

If you measure at mash temp, with a pH meter that is calibrated correctly, then yes, that is the mash temp pH. The problem with a lot of literature is that the authors don't specify the temp at which they took their measurements. That's pretty much the whole reason for this thread.

Brew on

Indeed, pH when read at mash temperature is the actual mash pH. Let's say we measure 5.40 pH at 152 degrees F., and at 45 minutes into a 60 minute mash. When this very same Wort sample is subsequently cooled to 68 degrees F. it is going to read ~5.62 pH (or there about). And for a well calibrated pH meter with ATC both readings are indicating the correct pH. And both are considered valid means of taking what is called a mash pH. @doug293cz has hit the nail on the head. It is rare when the temperature for a given pH reading is specified, even for peer reviewed brewing industry literature which spans from the discovery of the pH meter until today. And this critical oversight is both a shame and a blight on the science. The amateur presumption has been that when 5.4 pH is targeted as the ideal mash pH this means at room temperature, but a careful reading of much peer reviewed industry level documentation has led me to conclude that this amateur (including here amateur level 'experts') presumption is incorrect and when such industry level literature of yore mentions 5.4 pH it actually means 5.4 pH at mash temperature.

The consequence of this is that for mash pH readings taken at room temperature with a well calibrated ATC meter the ideal target is going to be around 5.55 to 5.65 pH, with the rather good presumption that if such a room temperature sample reading had instead been taken at around 150-155 degrees F. it would have been in close proximity to 5.40 pH.

Clearly a mash pH taken at mash temperature is superior in precision, and for that case 5.40 pH is the ideal target, but many to perhaps most budget pH meters are not built to take readings at such high temperatures.

 

[ScrewyBrewer]

Apparently the authors were not aware of differences in pH when sampled at room or mash temperatures.

 

[dmtaylor]

Apparently the authors were not aware of differences in pH when sampled at room or mash temperatures.

Or they just didn’t care because they wrote the textbooks before nerds from the 21st century started making erroneous assumptions.

 

[Silver_Is_Money]

Or they just didn’t care because they wrote the textbooks before nerds from the 21st century started making erroneous assumptions.

Indeed, if they were all taking mash pH's at mash temperature, there would be no need to tell anyone what was obvious.

 

[McKnuckle]

What's the TL;DR version of this when using brewing software to estimate the mash pH? Target 5.4-5.6 or something higher now?

 

[Qhrumphf]

And we end up back at the same point its always been at. It doesn't really matter unless you care what a text says for a text's sake. If your meter can handle the high temp measurements then strike what value at what temp gives you the results you want. 5.4 mash temp, 5.4 room temp, 5.6 room temp, whatever works. As long as you do it consistently and repeatably. Everything else looking for some hidden ideal in texts is mental masturbation that screams appeal to authority fallacy. I have consistently found for my system and process a room temp of 5.45 (normally, I go slightly higher for dark beers and significantly higher for Hefes) gets me what I want out of it. Practical will always, always trump theoretical.

 

[Silver_Is_Money]

What's the TL;DR version of this when using brewing software to estimate the mash pH? Target 5.4-5.6 or something higher now?

See post #555, paragraph 2.

 

[cire]

That would be true, for scientists... except for the fact that many (most?) brewers are not scientists.

Unequivocally so, postings on this and other brewing forums bear out your premise, just as universal applause won't greet opinions on this very subject.

I began brewing with a little knowledge of pH, but not knowing it was of any relevance to this subject. That mattered not as then, in 1963, pH meters were horrendously expensive, large and delicate apparatus requiring space on a laboratory bench. Then they were still much like the machine introduced at the American Chemical Society meeting in San Francisco as seen here. Although this was an improvement on that in Fig 1 of this paper given to the IoB in 1923, it wasn't made to be lugged inside a mash tun and take a measurement. When there were handheld pH meters, their cost would be prohibitive to any but businesses with large turnover, by when much information was already found and recorded for posterity. Some such findings are contained in that 1923 paper, which also records that these were from and of brewing British beers, Milds, Pale Ales and Stouts. Could that imply lagers were mashed at higher pH?

 

[McKnuckle]

See post #555, paragraph 2.

"The consequence of this is that for mash pH readings taken at room temperature with a well calibrated ATC meter the ideal target is going to be around 5.55 to 5.65 pH, with the rather good presumption that if such a room temperature sample reading had instead been taken at around 150-155 degrees F. it would have been in close proximity to 5.40 pH."

Sorry, that's not quite what I asked. I am not using a pH meter. I am relying on software like yours, Brewfather, etc., which simply estimates a pH. Previous wisdom was to aim for a software generated pH of 5.3 to 5.5. Has that changed?

Thanks

 

[dmtaylor]

What's the TL;DR version of this when using brewing software to estimate the mash pH? Target 5.4-5.6 or something higher now?

Target about 5.55-5.60 (as measured at room temperature, anyway!).

That's what I'm doing now based on all this. I am NOT sure how much it matters to final beer quality, but if I've been brewing wrong for the past 20 years, I figure I might as well brew wrong the next 5, 10, 20 years and see if maybe it makes some difference. I honestly don't know yet.

 

[Silver_Is_Money]

Sorry, that's not quite what I asked. I am not using a pH meter. I am relying on software like yours, Brewfather, etc., which simply estimates a pH. Previous wisdom was to aim for a software generated pH of 5.3 to 5.5. Has that changed?

Thanks

IMHO, yes. Target 5.55 - 5.6 as the mid-range for room temperature and 5.40 at mash temperature. Others may disagree. YMMV

 

[McKnuckle]

Got it, thanks. All the caveats too. Very interesting...

 

[Silver_Is_Money]

Unequivocally so, postings on this and other brewing forums bear out your premise, just as universal applause won't greet opinions on this very subject.

I began brewing with a little knowledge of pH, but not knowing it was of any relevance to this subject. That mattered not as then, in 1963, pH meters were horrendously expensive, large and delicate apparatus requiring space on a laboratory bench. Then they were still much like the machine introduced at the American Chemical Society meeting in San Francisco as seen here. Although this was an improvement on that in Fig 1 of this paper given to the IoB in 1923, it wasn't made to be lugged inside a mash tun and take a measurement. When there were handheld pH meters, their cost would be prohibitive to any but businesses with large turnover, by when much information was already found and recorded for posterity. Some such findings are contained in that 1923 paper, which also records that these were from and of brewing British beers, Milds, Pale Ales and Stouts. Could that imply lagers were mashed at higher pH?

Interesting to see that electronic pH meters existed back in 1923, whereas (per Wikipedia, at least) the first patent for a pH meter (by Beckman) was not issued until October of 1934. I wonder why it took from 1923 (or earlier) until 1934 for a patent to be issued? What might have set the patented meter apart from earlier efforts?

For grins, Beckman sold 444 pH meters in 1935, and grossed $60,000. That's $135 per meter.

 

[Vale71]

What might have set the patented meter apart from earlier efforts?

According to the application it was rugged enough to be somewhat portable and also didn't reqiuire a regulated power source so that a battery could be employed as the power source for portable units.

https://patents.google.com/patent/US2058761A/en
It basically led to modern portable meters suitable for field use.

 

[chrisgg]

What pH optima did he specify for "Wort" prior to adjusting it (either just pre, or during , or post boil) so as to achieve 5.0-5.2 post boil and cooling. I've expressedly stated that pH should be measured upon cooled Wort, but my distinction (and I believe also Weyermann's) is that at that juncture it is a Wort pH that one is measuring, and no longer is it technically a mash pH, whereby via the application of the Weyerman 0.22 point offset one sees a means to "presume" mash pH from "de-facto" wort pH.

The EBC standard for measuring Wort pH is to do so at 20 degrees C., but this does not make what is being measured a mash pH. Wort pH is at room temperature and mash pH is at mash temperature.

This is quite wrong. A lower pH reading at mash temperature does not mean the mash is more acid. Nor does a higher pH reading at a low temperature make it more alkaline. The pH scale was only designed to be used at 25°C and does not apply exactly at higher and lower temperatures. For example, at boiling point pure water is still neutral (same number of OH- and H3O+ ions) but its pH is 6.14. It is not more acid at boiling point. At 100°C a neutral pH IS 6.14. The pH value of 7.00 being neutral, only applies at 25°C. Room temperature is near enough to 25°C for most purposes but not exactly so. So there is absolutely no point in quoting a mash pH temperature unless you adjust the pH scale for the temperature of your mash. Decent pH meters adjust the pH reading automatically to what it would be at 25°C. Heat or cold does not make water or aqueous liquids more acid or more alkaline...it merely shifts the pH SCALE (not the pH) from its value at 25°C. See: Temperature Dependence of the pH of pure Water

 

[Silver_Is_Money]

This is quite wrong. A lower pH reading at mash temperature does not mean the mash is more acid. Nor does a higher pH reading at a low temperature make it more alkaline. The pH scale was only designed to be used at 25°C and does not apply exactly at higher and lower temperatures. For example, at boiling point pure water is still neutral (same number of OH- and H3O+ ions) but its pH is 6.14. It is not more acid at boiling point. At 100°C a neutral pH IS 6.14. The pH value of 7.00 being neutral, only applies at 25°C. Room temperature is near enough to 25°C for most purposes but not exactly so. So there is absolutely no point in quoting a mash pH temperature unless you adjust the pH scale for the temperature of your mash. Decent pH meters adjust the pH reading automatically to what it would be at 25°C. Heat or cold does not make water or aqueous liquids more acid or more alkaline...it merely shifts the pH SCALE (not the pH) from its value at 25°C. See: Temperature Dependence of the pH of pure Water

I beg to differ, and contend that Weyermann is fundamentally correct in recording a roughly 0.22 pH point difference between a Wort measured at 67 degrees C. and then subsequently measured at 20 degrees C.

An ATC pH meter does not correct pH values to 25 degrees C. It assures that the reading will be more in line with being correct at temperatures other than the calibration temperature. But for a meter calibrated at 25 degrees C. the Wort will read about 0.22 points lower than it will at mash temperature, as the referenced Weyermann literature clearly indicates.

Clearly and technically you can argue (precisely as you are doing) that DI water always has the same amount of extant hydroxyl and hydronium ions, such that regardless of temperature, it is de-Facto neutral. But without an understanding of the slope offset, one can not assume that an actual measured 5.40 pH Wort at 67 C. will also read on the display of the ATC meter the very same 5.40 pH when at the appropriate 20 degrees C. (as per EBC) or at the appropriate 25 degrees C. (per many meters accompanying literature) simply due to the presence of ATC alone. What will be observed for a 5.40 at full mash temperature Wort pH will be observed to be somewhere around a 5.62 pH when read by the same instrument at 20 degrees C.

So what is incorrect is your statement that "Decent pH meters adjust the pH reading automatically to what it would be at 25°C.".

Will ATC adjust the measured sample pH result to the result expected at 25°C? Does it work like conductivity temperature compensation? No, ATC does not work like conductivity temperature compensation. We cannot adjust a measured sample pH value at one temperature to an expected sample pH value at another temperature (e.g. 25°C), because we do not know how the pH of a sample varies with temperature. For example, the pH value of a water sample may change rapidly as the result of chemical, physical, or biological processes that are temperature dependent. If we want to know what the pH value of the sample is at a certain temperature, we would have to adjust the sample to that temperature and measure the pH. That is why pH is frequently reported with a temperature measurement. We understand that the pH of a sample is temperature dependent. While ATC does allow us to calibrate accurately and adjust the pH electrode calibration when the temperature changes, ATC can’t correct for sample pH/temperature effects, which are unknown.

Source: https://assets.thermofisher.com/TFS...p-Compensation-pH-Measure-ST-ATCPHMEAS-EN.pdf